JP3385909B2 - Filter and transceiver - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter which can be produced by processing a good conductor, and corresponds to, for example, a combline filter. This combline filter can be used in transceivers in the fields of radar, satellite communication, etc., where low loss / high rejection filters are required. Hereinafter, the filter according to the present invention will be described by taking a combline filter as an example.

[0002]

2. Description of the Related Art FIG. 12 is a block diagram of a conventional combline filter. In the figure, 1 is an input / output connector, 31 is a case lid, 32 is a filter case, 4 is a resonator, 5 is an adjusting screw, 7 is a screw connecting the filter case 32 and the case lid 31 to each other, and 8 is an adjusting screw 5. It is a nut provided corresponding to. Further, FIG. 13 shows the structure of another conventional combline filter, and the same elements as those in FIG. 12 are denoted by the same reference numerals.

Next, the structure of a conventional combline filter will be described. In the structure of the conventional combline filter shown in FIG. 12, the resonator 4, the case lid 31, and the filter case 3 are included.
2 are separate parts from each other. Then, the resonator 4 is bonded to the filter case 32 by a method such as brazing, and the case lid 31 is connected to the filter case 32 by screwing, brazing or the like. A screw hole is opened in the case lid 31, and the adjusting screw 5 is inserted into this screw hole.

In FIG. 13, the structure is such that the filter case 2 and the resonator 1 are integrally formed by shaving, and the case canopy 3 is screwed or brazed on the integrated filter case. Connected by.
Further, the hole of the adjusting screw 4 is opened in the case lid 3.

[0005]

Although a high frequency current flows through the conventional combline filter as described above, the resonator 4
It is generally known that the current is particularly concentrated and distributed in the joint portion with the filter case 32 and the connector core wire portion. Therefore, when the portion where the current is concentrated is separated from the filter case 32, the loss due to the deterioration of the circuit Q is increased, and there is a problem that a filter different from the design characteristic is completed.

Further, there is a problem in that it is difficult to obtain the positional accuracy when the resonator 4 is attached to the filter case 32. Due to the positional deviation of the resonator 4, the band characteristic of the filter is deviated, the input / output reflection characteristic is deteriorated, and the like. It was happening. These become more prominent as the frequency becomes higher, and the deterioration of the characteristics at tens of GHz or more becomes prominent.

Further, in the conventional combline filter as shown in FIG. 13, since the resonator 4 and the filter case 32 are integrated by shaving and the like, the problem of the positional accuracy of the resonator 4 described above is a problem. Will be resolved. Here, the resonator 4 and the adjusting screw 5 should not be in contact with each other, but when the adjusting screw 5 is inserted into the filter case 32 through the screw hole of the case lid 31, if the case lid is in the frequency band as described above. Depending on the mounting precision of 31 and the precision of tapping the adjusting screw 5, the design dimensions are often such that the resonator 4 and the adjusting screw come into contact with each other. This means that the case lid 31 has a filter case 32 even in the combline filter of FIG.
Since it was a separate body, it caused the same problem.

Further, since the adjusting screw 5 is inserted into the screw hole of the case lid 31, the adjusting screw 5 has a threaded shape as a whole. However, such a shape causes energy loss and insertion loss as a filter. Was being increased.

Further, in FIG. 13, the connector core wire 1 and the resonator 4 are directly connected, and another mechanism is provided outside the combline filter in order to prevent impedance mismatch and deterioration of reflection characteristics. As a result, inconsistency may be corrected, and the structure is complicated.

The present invention has been made to solve the above problems, and by devising the structure,
The common purpose is to obtain a filter with higher accuracy and closer to the design value.

[0011]

Means for Solving the Problems] full <br/> filter according to a first aspect of the invention, a plurality of resonators that are arranged in the longitudinal direction, at both ends
A tap formed on the outside of the resonator in the longitudinal direction.
Filter case and the case lid that covers the resonator
Electric discharge machining and shaving from the direction perpendicular to the longitudinal direction on the material
The resonator and the tap portion are processed by subjecting
And a filter case formed with the case lid,
Formed on both ends of the filter case in the longitudinal direction
Connected I / O connector and this I / O connector
Connector core wire and the connector core wire
The fixing means that is brought into contact with and fixed to the above, and the filter case.
Both covers the release part released in the direction perpendicular to the longitudinal direction
The side plate and the case lid are provided, and the center circumference of each resonator is
It is provided with an adjusting screw for adjusting each wave number .

[0012] filter according to the invention of claim 2, wherein the co
Shaker, tap section, case lid section, filter case
The filter according to claim 1, wherein the base and the both side plates are plated with silver .

According to a third aspect of the present invention, there is provided the filter according to
The top portion has a rectangular shape.

According to a fourth aspect of the present invention, there is provided a filter according to
The material of the filter case is brass .

According to a fifth aspect of the present invention, the resonator has a prismatic shape .

A transmitter / receiver according to the invention of claim 6 is
The filter according to any one of claims 1 to 5 is provided .

[0017]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. FIG. 1 is a configuration diagram of a combline filter according to the first embodiment. 1 (a) is a top view, FIG.
1B is a plan view, FIG. 1C is a left side view, and FIG. 1D is a right side view.

In the figure, 1 is an input / output connector to which lead lines for input / output signals are connected, 2 is a tap integrally provided on a part of a resonator 4 described later, and 3 is a resonance described later. 4 is a filter case that houses the resonator 4 therein, 4 is a resonator, and 5 is an adjusting screw for adjusting the frequency of the resonator 4. A plurality of resonators 4 are provided in the filter case 3, and an adjusting screw is provided for each resonator 4. 6 is a side plate that covers the side surface of the filter case 3, and 7 is a fixing screw for fixing the side plate 6.

FIG. 2 is a diagram showing a divisional state of the combline filter shown in FIG. However, in FIG. 2, the fixing screw 7 of the side plate 6 and the screw hole used for fixing the connector 1 are omitted for the sake of simple description of the configuration.

In FIGS. 1 and 2, a filter having six resonators is taken as an example. The material for the filter structure is brass, which is easy to process and inexpensive. In the combline filter according to this embodiment, the side plate 6 can be removed from the filter case 3 as can be seen from the divided state diagram of FIG. 2, but the filter case 3 itself, the filter case 3, the resonator 4 and the taps. Two
And form an integrated structure together.

The machining of this integrated structure is produced by performing electric discharge machining and shaving from a direction perpendicular to the length direction of the resonator 4. In order to perform such electric discharge machining and shaving, the side portion of the filter case 3 is open as shown in FIG.

Then, the released filter case 3
The side plates 6 are arranged so as to be sandwiched between two side plates 6, and the side plates 6 are fixed by fixing screws 7. By providing the side plate 6 in this way, the conduction of the entire filter can be ensured. The material of the side plate 6 is brass, which is the same as the material of the filter case 3. When the combline filter is functioning, a high frequency current flows through this side plate 6.

A screw hole is formed on the upper surface of the filter case 3, and the adjusting screw 5 is inserted into the filter case 3 through the screw hole. When the adjusting screw 5 is inserted into the screw hole, the screw thread of the adjusting screw 5 and the screw hole of the filter case 3 are fitted to each other. Each of the resonators 4 has a prism shape, and the prism has a hollow structure. Therefore, when the adjusting screw 5 is inserted, the tip portion of the adjusting screw 5 is inserted into the cavity of the resonator 4. Further, the filter case 3 in this embodiment is one in which the case lid 31 and the filter case 32 of the conventional combline filter shown in FIGS. 12 and 13 are integrally formed.

In the present embodiment, since brass is used as the material, its conductivity is low. Therefore, the integrated tap 2, filter case 3, resonator 4 and side plate 6 are silver-plated to improve the conductivity of the filter surface. The base treatment for silver-plating brass is common.

Such a resonator 4 and filter case 3
There are the following two advantages as an integrated structure.
First, since the high frequency current flowing through the junction between the resonator 4 and the filter case can be handled with a low loss by being integrated, the insertion loss as a filter can be reduced.

The second point is that the filter can be constructed in a form very close to the design value and the characteristics can be easily obtained. This is because the dimensional tolerance is small and the mounting position accuracy is improved as compared with the case where the resonator 4 and the filter case 3 are separately assembled. In particular, in this embodiment, since the tap 2 is also integrated with the filter case 3 and the resonator 4, it is possible to further reduce the positional deviation at the time of mounting and obtain a characteristic close to the design. Become.

Further, in the case of the resonator 4 shown in this embodiment, the adjusting screw 5 is inserted into the hole of the resonator 4, but in this case, the resonator 4 and the adjusting screw 5 are inserted. You must keep out of contact with. Furthermore, dozens of GH
In the high frequency region of z, the overall structure becomes small and the dimensional conditions become strict. From the above, the mounting position accuracy is important in order to improve the characteristics of the filter, and it is effective to make the filter case 3, the tap 2 and the resonator 4 all have an integrated structure under such conditions.

Furthermore, in this embodiment, the filter case 3 is obtained by integrally forming the conventional case lid 3 and the filter case 32 shown in FIGS. It is also effective in that it is not necessary to consider the attachment accuracy when attaching the case lid 31 to the filter case 32 which has been used.

Embodiment 2. FIG. 3 is a structural diagram of the combline filter in this embodiment. In this embodiment, the resonator 4 has a cylindrical shape as shown in FIG. 3, and is different from the previous embodiments in that it is not hollow. Other configurations are similar to those of the previous embodiment, and the filter case 3 and the cylindrical resonator 4a are integrally formed by electric discharge machining or shaving which is perpendicular to the length direction of the resonator. In addition, the adjusting screw 5 is inserted into the cylindrical resonator 4a through a screw hole formed in the upper surface of the filter case 3, and the coupling amount can be adjusted. The resonator 4a and the adjusting screw 5 are adjusted by the adjusting screw 5 so as not to come into contact with each other.

The cylindrical resonator 4 in this embodiment
a is used in the case of a filter design that requires a relatively small coupling capacitance. Further, the cylindrical resonator 4a is effective in that the structure is not hollow and the shaving process is simple. Also in this embodiment, as in the previous embodiments, the filter case 3 itself, the filter case 3, the tap 2 and the resonator 4a have an integrated structure, so that the filter case 3 is constructed in a form very close to the design value. The characteristics can be easily obtained.

Embodiment 3. FIG. 4 is a diagram showing the structure of the combline filter in this embodiment. This embodiment differs from the previous embodiments in that the resonator 4b has a cylindrical shape as shown in FIG.

The other structure is the same as that of the previous embodiment, and the filter case 3 and the cylindrical resonator 4b are provided.
Is integrally formed by electric discharge machining or shaving from the direction perpendicular to the resonator 4b. The adjusting screw 5 is inserted into the cylindrical resonator 4b through a screw hole formed in the upper surface of the filter case 3.

Even in this case, since the filter case 3 and the resonator 4b are integrally formed, the cylindrical resonator 4b and the adjusting screw 5 can be spatially coupled without contacting each other. Further, the coupling capacitance between the resonator 4b and the adjusting screw 5 can be increased.

Also in this embodiment, as in the previous embodiments, the filter case 3 itself, the filter case 3, the tap 2 and the resonator 4b have an integrated structure, and therefore are very close to the design values. It can be constructed in a shape and the characteristics can be easily obtained.

Fourth Embodiment FIG. 5 is a diagram showing the structure of the combline filter in this embodiment. In this embodiment, as shown in FIG. 5, the resonator 4c has a quadrangular prism shape and is different from the previous embodiments in that it is not hollow. Other configurations are similar to those of the previous embodiment, and the filter case 3 and the quadrangular prism type resonator 4c are provided.
Is integrally formed by electric discharge machining or shaving from a direction perpendicular to the length direction of the resonator 4c. Further, the adjustment screw 5 is inserted into the rectangular prism type resonator 4c through a screw hole formed in the upper surface of the filter case 3,
It is possible to adjust the binding amount.

The quadrangular prism type resonator 4c in this embodiment is used in the case of designing a filter that requires a relatively small coupling capacitance. In addition, the quadrangular prism type resonator 4c is
Since it is not hollow, the structure is simplified, and it is effective in that shaving and the like are easy. Further, also in this embodiment, as in the previous embodiments, the filter case 3 itself, the filter case 3, the tap 2 and the resonator 4 have an integrated structure, so that the configuration is extremely close to the design value. The characteristics can be easily obtained.

Embodiment 5. FIG. 6 is a diagram showing the structure of the combline filter in this embodiment. In this embodiment, as shown in FIG. 6, the resonator 4 is of a rectangular tube type.

The other structure is the same as that of the previous embodiment, and the filter case 3 and the square tube resonator 4d.
Is integrally formed by electric discharge machining or shaving from a direction perpendicular to the length direction of the resonator 4d.
Further, the adjusting screw 5 is inserted into the square-shaped resonator 4d through a screw hole formed in the upper surface of the filter case 3, and the amount of coupling can be adjusted.

Also in this embodiment, as in the previous embodiments, the filter case 3 itself, the filter case 3, the tap 2 and the resonator 4d have an integrated structure, and therefore are very close to the design values. It can be constructed in a shape and the characteristics can be easily obtained. In addition, since the resonator 4d has a prismatic shape, it can be easily processed when integrally formed with the filter case 3.

Sixth Embodiment FIG. 7 shows a combline filter in this embodiment. In order to join the input / output connector 1 and the resonator 4, the tap 2 is placed and joined. FIG. 7 is a diagram showing a state where the input / output connector 1 and the resonator 4 are joined, and the input / output connector 1 and the resonator 4 are connected via the connector core wire 8 and the tap 2. Here, the input / output connector 1 and the tap 2 are integrated with the filter case 3. With this tap 2, the coupling strength and impedance can be adjusted.

The shape of the tap 2 is, for example, as shown in FIG.
As shown in (a) and (b), a columnar shape, a rectangular shape, and the like are possible, and the strength of the bond can be changed by the shape of the tap 2.

Furthermore, impedance matching can be achieved by changing the aspect ratio of the tap 2 and the position of the tap 2 with respect to the resonator 4. Specifically, FIG.
As shown in (c), when the tap 2 has a square shape, the vertical and horizontal size ratios (corresponding to the aspect ratio) are adjusted, or the position where the tap 2 is provided in the resonator 4 is adjusted to reduce the impedance. Matching can be achieved.

FIG. 9 is a diagram showing an example of how to join the connector core wire 8 and the tap 2. In FIG. 9, the connector core wire 8 and the tap 2 are extracted and described for simplification. FIG. 9 shows a case where a groove is formed in the tap 2 and the connector core wire 8 is inserted in that portion. Connector core wire 8 and tap section 2
Conduction of b is performed by soldering 9 or a conductive adhesive to fill the groove.

In this embodiment, since the tap 2 and the resonator 4 are integrated, the positional accuracy of the tap 2 with respect to the resonator 4 can be ensured. As described above, the position of the tap 2 with respect to the resonator 4 influences impedance matching, so that by obtaining a more accurate position, it becomes possible to obtain an impedance characteristic closer to the design value.

Embodiment 7. FIG. 10 is a diagram showing the shape of the adjusting screw used in the combline filter in this embodiment. The adjusting screw 5a is used for the resonator 4
It has a shape with no threads at the part that is inserted into the internal cylinder. When there is no screw thread, there is a difference in the loss of the current flowing on the surface compared with when there is a screw thread.

The loss of the current flowing on the screw surface with and without the screw thread will be described in detail. When the combline filter is functioning, a high frequency current also flows through the adjusting screw 5a. This high frequency current is
It has a characteristic that it flows concentratedly on the surface of the conductor, that is, the surface of the adjusting screw 5a.

In the case of the adjusting screw 5a having a thread,
Due to the above characteristics, the high frequency current flows on the surface of the unevenness of the screw thread. Therefore, when comparing the adjusting screw having the same length of the screw thread and the adjusting screw having no screw thread, the distance at which the high frequency current flows is longer in the adjusting screw having the screw thread. Further, since the screw threads are quite sharp, radiation and heat generation are likely to occur at the edge portions of the screw threads. For the above reason, the loss of the high frequency current flowing on the surface is smaller when the thread is not provided than when the thread is provided.

As a result, a low-loss filter in which the circuit Q as the resonator 4 is enhanced can be constructed. Further, the adjusting screw 5a needs to be inserted into the inner cylinder of the resonator 4 without contacting it. However, the adjusting screw 5a may contact the inner cylinder of the resonator 4 due to the absence of threads. There is also the effect of decreasing.

Embodiment 8. FIG. 11 is a diagram showing the shape of the adjusting screw used in the combline filter. The adjusting screws 5b and 5c are JI screws having a standard diameter of a portion to be inserted into the resonator 4 that is generally used.
It is configured to be smaller than the diameters of the S and ISO screws.

With this structure, a screw thread conforming to the standard can be used for the threaded portion, and the diameter of the portion inserted into the cylinder of the resonator can be designed. . As a result, the diameter of the portion of the adjusting screw 5 to be inserted in the cylinder of the resonator can be designed with a high degree of freedom according to the small application of the filter.

The threaded portion of the adjusting screw is fixed by screwing it on the filter case 3 facing the resonator 4, and the threaded portion is JI.
By keeping the shape according to the S and ISO standards,
The thread of the adjusting screw 5 and the screw hole of the filter case 3 can be created using a standard tool.

Although a plurality of embodiments are separately described in this specification, the combline filter may be configured by appropriately combining the embodiments. Further, in this specification, the embodiment has been described by taking the combline filter as an example, but the invention is not limited to the combline filter and can be applied to other filters.

According to the present invention, a plurality of resonators and taps
The filter case, which has
As a result, the resonator and the
To improve the mounting position accuracy and reduce insertion loss
And filter characteristics close to the design value can be easily obtained.
it can.

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[Brief description of drawings]

FIG. 1 is a configuration diagram of a combline filter according to a first embodiment.

FIG. 2 is a diagram showing a division state of a combline filter according to the first embodiment.

FIG. 3 is a structural diagram of a combline filter according to a second embodiment.

FIG. 4 is a structural diagram of a combline filter according to a third embodiment.

FIG. 5 is a structural diagram of a combline filter according to a fourth embodiment.

FIG. 6 is a structural diagram of a combline filter according to a fifth embodiment.

FIG. 7 is a structural diagram of a combline filter according to a sixth embodiment. It is a figure which shows an example of how to join the connector core wire 8 and the tap 2.

FIG. 8 is a diagram showing the shape and dimensions of the tap 2.

FIG. 9 is a diagram showing an example of how to join the connector core wire 10 and the tap 2.

FIG. 10 is a diagram showing an adjusting screw according to a seventh embodiment.

FIG. 11 is a diagram showing an adjusting screw according to the eighth embodiment.

FIG. 12 is a structural diagram of a conventional combline filter.

FIG. 13 is a structural diagram of another conventional combline filter.

[Explanation of symbols]

1 input / output connector, 2 taps, 3 filter case, 4 resonator, 5 adjusting screw, 6 side plate, 7 fixing screw, 8 nut, 9 adhesive, 10 connector core wire.

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Claims (6)

(57) [Claims] 1. A plurality of resonators arranged longitudinally, both
Formed on the outer side in the longitudinal direction of the end resonator
The tap case and the case lid that covers the resonator are
Electrical discharge machining from the direction perpendicular to the longitudinal direction to the base material and
The resonator and the tap are processed by performing a cutting process.
A filter case formed with a cap portion and the case lid portion,
At both ends of the filter case in the longitudinal direction,
Connect the formed I / O connector to this I / O connector.
Connect the connected connector core wire and this connector core wire to the
Fixing means which is brought into contact with and fixed on the filter part, and the filter.
Cover the released part in the direction perpendicular to the longitudinal direction of the case.
On both side plates and the case lid, inside each resonator
A filter having an adjusting screw for adjusting each of the heart frequencies . 2. The resonator, the tap portion, and the case
Silver plating on the lid, the filter case and both side plates
The filter according to claim 1, which is applied . 3. The tap portion has a rectangular shape.
The filter according to claim 1, which is a characteristic . Wherein said filter case material A filter according to claim 1, characterized in that the brass. Wherein said resonator filter according to claim 1, characterized in that a prismatic. 6. The method according to any one of claims 1 to 5.
A transmitter / receiver characterized by being equipped with a filter.